Allergenic Cross-Reactivity between <i>Callistemon citrinis</i> and <i>Melaleuca quinquenervia</i> Pollens

Abstract

Aqueous extracts of both Callistemon citrinis (bottlebrush) and Melaleuca quinquenervia (melaleuca) were analyzed for allergenic cross-reactivity. Inhibition analysis using the radioallergosorbent test (RAST) was performed on the ammonium bicarbonate extracts of bottlebrush (NH₄B) and melaleuca (NH₄M) pollens. RAST inhibition analysis demonstrated that the extracts contained allergenically cross-reactive components. Sephadex G-100 column chromatography of NH₄B and NH₄M extracts resulted in at least 4 distinct peaks for each extract analyzed. These fractions were designated NH₄B1-NH₄B4 and NH₄M1-NH₄M4. A modified dot-blot assay for detection of allergenic components was utilized to show that the first elution peaks of bottlebrush and melaleuca, NH₄B1 and NH₄M1, respectively, contained allergenic components. These allergenic components, NH₄B1 and NH₄M1, had estimated molecular weights of 50,000 and 35,000 daltons, respectively.

Immunodetection and Comparison of Melaleuca, Bottlebrush, and Bahia Pollens

“…Regardless of which extract was analyzed for antigenic as well as allergenic cross-reactivity, the studies reported here and previously [1,2] strongly suggest the existence of immunological cross-reactivity among the three pollens.…”

IgE-Binding Proteins from Pine (<i>Pinus radiata</i> D. Don) Pollen: Evidence for Cross-Reactivity with Ryegrass <i>(Lolium perenne)</i>

“…Cross-reactivity between closely related species has been well documented for grasses [12,17,18] and trees [17,19,20]. Cross-reactivity between unrelated species seems much rarer, but Howlett et al [21] demonstrated cross-reactivity between Acacia and ryegrass pollen allergens using RAST inhibition stud ies similar to those applied here.…”